Syntheses and metal complexes of a quadridentate NNSS ligand derived from S-benzyl dithiocarbazate (H2L) and crystal structure of the complex of CuL

The quadridentate "N2S2" Schiff base ligand, H2L, prepared by the condensat ion of S-benzyl dithiocarbazate with 1,4-bis(2'-formylphenyl)-1,4-dioxabuta ne in a 2:1 molar ratio, reacts with divalent metal ions to form the neutra l metal complexes, ML (M=Ni, Cu, Zn). The complexes have been characterized by physico-chemical techniques and the single crystal X-ray structure of t he Cu(II) complex shows the geometry around the metal atom to be distorted square planar. The monomeric units are weakly associated into dimers via a long Cu-S interaction [2.9519(8) Angstrom]. (C) 1998 Elsevier Science Ltd. All rights reserved.